Conventionally, almost all methods of administering a chemical, etc., to a patient's living organism surface, i.e., the surface of a skin or a mucous membrane are methods of applying a liquid substance or powder substance. Since, however, the region to which a medical agent can be applied is limited to a skin surface, it is a daily experience to have an applied medical agent come unstuck due to sweating or a contact of a foreign matter, and it has been hence difficult to effectively administer a proper dose of a medical agent, etc.
As the alternative to the application of a medical agent to a living organism surface, there is proposed a method of administering a medical agent into a living organism with a microneedle. Further, there have been so far made proposals to improve the above microneedle in puncturing ability.
For example, Patent Documents 1 and 2 propose microneedles and microneedle arrays that are neither easily bendable nor easily curvable and methods of producing them. However, they have no sufficient puncturing ability.
Patent Document 3 proposes a method in which a surface of a circular cone or surfaces of a pyramid of a microneedle are curved inwardly to make it easily run into. However, the method disclosed in Patent Document 3 is a method that uses a volume contraction when a polymer solution is applied to a stamper and gelation-dried, and it is not suitable for thermoplastic resin.
Patent Document 4 describes a microneedle which is formed from a water-soluble or water-swellable resin and which has the form of a cone, a frustum of cone or “Konide” and has a surface coated with a lubricant component.
(Patent Document 1) JP-A 2007-130030
(Patent Document 2) JP-A 2007-190112
(Patent Document 3) JP-A 2008-142183
(Patent Document 4) JP-A 2010-029634